In Japan, huge passenger traffic moves through the Tokyo-Osaka corridor and the demand is mounting for another high speed line besides the Tokaido Shinkansen. A magnetically levitated vehicle (JR Maglev) using superconducting magnets has been developed for the Tokyo-Osaka superspeed express. JR Maglev has many advantages over conventional rail systems. This paper describes the necessity of another high speed line in this corridor, the reason for the selection of Maglev, the scheme of this system, the history of the development and outline of the new Yamanashi test line project